1. Field of the Invention
Embodiments of the present invention generally relate to a method and apparatus for converting data for use in different power supply voltage domain, and more specifically, to a supply-modulation cross-domain data interface.
2. Description of the Related Art
Input devices including proximity sensor devices (also commonly called touchpads or touch sensor devices) are widely used in a variety of electronic systems. Proximity sensor devices may be used to provide interfaces for the electronic system. For example, proximity sensor devices are often used as input devices for larger computing systems (such as opaque touchpads integrated in, or peripheral to, notebook or desktop computers). Proximity sensor devices are also often used in smaller computing systems (such as touch screens integrated in cellular phones). A proximity sensor device typically includes sensor electrodes that are driven with signals for capacitive sensing.
Some proximity sensor devices are included in display devices that include display electrodes for updating display elements. In order to guard the sensor electrodes from the display electrodes, the sensor electrodes and display electrodes may be powered by a modulated power supply that is modulated with respect to a system ground. In such an input device, some components are coupled to the modulated power supply, while other components may not be coupled to the modulated power supply. Because the power supply voltages differ, data signals from a component that is coupled to the modulated power supply may not be compatible with a component that is not coupled to the modulated power supply.
As the foregoing illustrates, what is needed in the art are techniques for transmitting data signals from a component that is not coupled to a modulated power supply to a component that is coupled to the modulated power supply.